Left atrial posterior wall isolation using very high-power short-duration in patients with persistent atrial fibrillation

Background: Pulmonary vein isolation (PVI) is the fundamental procedure used to treat atrial fibrillation (AF). Nevertheless, the presence of extra-pulmonary foci continues to provide a challenge in patients with persistent AF. Recent advancements in ablation techniques, such as very high-powered short-duration (vHPSD) ablation, have shown encouraging outcomes in the treatment of pulmonary vein isolation (PVI). However, there is a lack of evidence on vHPSD-ablation for the posterior wall substrate in cases of persistent AF ablation.

Objective: The study aimed to evaluate procedural characteristics, acute success, as well as safety of vHPSD ablation for posterior wall isolation (PWI) beyond pulmonary vein isolation (PVI) in patients with persistent AF.

Methods: A total of 108 patients who received PWI beyond isolation of the pulmonary veins between January 2022 and April 2024 were included in this analysis. PWI was performed in patients who had arrhythmia recurrence after initial AF ablation and evidence for a posterior wall substrate from bipolar voltage mapping. PWI was conducted either as stand-alone therapy (when PVI from the index procedure was sustained) or in addition to repeat PVI (when there was PV reconnection). The ablation approach included the creation of a box-shaped lesion, consisting of a left atrial roof and botton line in addition to the posterior lesion sets for PVI. Therefore, vHPSD ablation with a power output of 90 Watts over 4 seconds was used at all locations at the posterior LA wall. 

Results: The study included 108 patients (mean age 67±11 years, 62% male) who had persistent AF recurrence after initial ablation. The mean CHA2DS2-Vasc Score was 2.6±1.52 points, and the mean LVEF was 51.42±8.28%. Procedure duration was 89.06±16.56 minutes, while the fluoroscopy time was 5.8±3.69 minutes. The mean ablation duration to achieve PWI (including roof and bottom line) was 46±6 seconds. Acute procedural success was 92.59% and we observed no relevant procedure related complications. Over a 12-month follow-up period, freedom from arrhythmia recurrence was 83%.

Conclusion: LA PWI with vHPSD is a safe and effective procedure for patients with recurrent AF and a posterior wall substrate. It decreases the likelihood of arrhythmia recurrence during follow-up in patients with persistent AF and need for repeat ablation. Further investigation is necessary to verify the validity of these findings.

Figure1: PWI using vHPSD (90 watt). A) Voltage map in SR showing substrate on the PW, B) PVI and PWI with roof and bottom line, C) Voltage map after PVI and PWI with ablation lines, D) voltage map in SR after PVI and PWI without ablation lines.